Stay-bolt for boilers



J. R. FLANNERY AND E. I. DODDS.

STAY BOLT FOR BOILERS. APPLICATION FILED FEB, 21. 1917.

1,3 1 3,627 Patented Aug. 19, 1919. 1

IV/T/VESSES an. M

6. 7 1} W A/ om rs determine the condition of the UNITED STATES PATENTOFFICE,

7 JOHN ROGERS FLANNERTAND ETHAN I. norms, or PITTSBURGH, PENNSYLVANIA,

ASSIGNORS To FLANNERY BOLT COMPANY, or

,"PITTSBURG-H, PENNSYLVANIA.

STAY-BOLT FOR BOIIPERS.

county of Allegheny and State of Pennsyl- "ania, have invented certainnew and useful Improvements in Stay-Bolts for Boilers,

and we do hereby declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart in which. it appertains to make and use the same.

This invention relates to improvements in staybolts for boilers and moreparticularly to such as are provided with tell-tale holes.

Heretofore in the construction of flexible stay-bolts for boilers, ithas been proposed to provide the bolt with a tell-tale hole, so that inthe event of rupture of the bolt, Water or steam or both could enter thebore or tell-tale hole and by its presence therein or discharge fromtheouter end thereof, indicate the ruptured condition et. the bolt. Wefind it undesirable in many instances to permit the tell-tale hole tofreely discharge through the outer headed end of the bolt and theefliciency of the tell-tale hole is also reduced by the accumulationofcinders and dirt therein, unless means be provided to prevent the same.

The object of our present invention is to provide a stay bolt structurehaving a telltale hole or bore which shall extend from the inner end ofthe same and in which. said inner end shall be sealed or temporarilyclosed by a plug which will serve to keep the bore clean; which shallwithstand the heat in the fire box for aconsiderable period, but whichseal or plug may be easily removed to permit inspectiont'of thetelllj-tlale hole to With this and other objects in view, theinvention'consists in certain novel features of construction ashereinafter set forth and pointed out in the claims.

the accompanying drawings; Figure 1 is a longitudinal sectional viewshowing a staybolt embodying our invention, and Fig. 2 is a sectionalview showing the applica- Specification of Letters Patent.

Application filed February 21, 1917. Serial No. 150,205.

spherical head 5' to tion of our invention to a somewhat difi'erentconstruction ofstaybolt.

1 represents the bod ed at its inner end 2 to e screwed to the innerboiler sheet 3 and upset as at 4. In theconstruction shown in Fig. 1,the bolt is provided at its outer end with a spherical or partly haveamounting at the outer boiler sheet, as is well understood. The body ofthe bolt is provided with a longitudinal bore which forms a tell-talehole 6 extending from the inner end of the bolt body to the headed endofthe bolt and terminating within the head 5, so that if the bolt shouldbecome ruptured at any, point between the both would be admitted intosaid tell-tale hole and serve to denote the rupture-d condition of thebolt.

In order that the tell-tale hole shall be kept clean, its innerdischarge end is temporarily closed by means of a plug 7 which may beremoved when it is desired to inspect the tell-talehole. This plug willbe made of a material which of the firebox for a considerable time butwhich may be blown out in case a general ruptureof the bolt takes place.The plug may be conveniently made of graphite which will serve thepurpose as above explained and which may be easily bored out ordisintegrated and removed with the use of a suitable tool.

In the construction shown in Fig. 2, the bore 6 extends throughout theentire length of the bolt, with a removable plug 7 such as abovedescribed temporarily closing its inner end and a metal plug 8 'fixedlysecured in and permanently closing said bore at the outer end of thebolt.

Having fully described our invention What We claim as new and desire tosecure by Letters-Patent, is

1. A stay bolt having a tell-tale hole permanently closed at its outerend, and having a removable plug closing the inner end of said tell-talehole.

2. A' stay bolt having a tell-tale hole ex-- tending from the inner tothe outer end of Patented Aug. 19, 1919.

of a staybolt threadboiler sheets, waiter or steam or.

will withstand the heat the bolt, said hole permanently closed at Intestimony whereof we have signed this 10 one end of the bolt andremovable means specification in the presence of twosubscribtenllprafiilyl zlzlosing said hole at the other ing witnesses.en 0 t e o t. I 5 a. A headed stay bolt having atell-tale gggg holeextending longitudinally from the inner end of the bolt into but notthrough the "Witnesses:

headed end of the bolt and having a plug F. H. ALLISON, in the inner endof said tell-tale hole. EDWIN S. Rrcn.

